EMBRYOLOGY
NERVOUS SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Sodium
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Potassium
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Calcium
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ACTH
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Detailed explanation-1: -In neurons, the rapid rise in potential, depolarization, is an all-or-nothing event that is initiated by the opening of sodium ion channels within the plasma membrane. The subsequent return to resting potential, repolarization, is mediated by the opening of potassium ion channels.
Detailed explanation-2: -Action potentials are caused when different ions cross the neuron membrane. A stimulus first causes sodium channels to open.
Detailed explanation-3: -Opening of the sodium channels in the axon membrane causes depolarization. The membrane suddenly becomes permeable to sodium ions. The membrane potential rises rapidly in the positive direction as the inflowing positively-charged sodium ions neutralize the normal polarized state which is-90 millivolts.